Description Healthy Hen™ Egg-Stra Eggs Water Additive 16 oz. If you want to boost egg production, simply add 3 caps full per gallon of fresh water. Calendula oil is extracted from marigolds and has been noted for anti-inflammatory properties, increasing blood flow and stimulating egg laying. The fennel and marjoram have both been noted as a laying stimulant. The thyme oil has been noted for immune boosting properties.